Re: [PATCH] hrtimer: Replace cpu_base->active_bases with a direct check of the active list

[Peter Zijlstra]

On Thu, Apr 09, 2015 at 08:28:41AM +0200, Ingo Molnar wrote:
> Btw., does cpu_base->active_bases even make sense? hrtimer bases are 
> fundamentally percpu, and to check whether there are any pending 
> timers is a very simple check:
> 
> 	base->active->next != NULL
> 

Yeah, that's 3 pointer dereferences from cpu_base, iow you traded a
single bit test on an already loaded word for 3 potential cacheline
misses.
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